You won't be able to OC that system cause it's a Dell and they are FSB locked

If you really want to OC that system, a new mobo and PSU are needed (mobo cause it's the Dell mobo that's locking the FSB and PSU cause Dell PSU's have the wires all screwed up and won't work with anything else except Dell's stuff).

believe me, i was feeling the same way you were when i found out. I just researched some motherboars, psu's and cooling solutions and asked around. do the same thing if you want to overclock. if you have a fast processor, like i do, (2.8 P4), just gently take it off of the dell motherboard and gently place it into the new motherboard that will allow you to overclock. make sure that you have a good psu, as they are key to getting a good oc. if you post what your probable budget is, i, along with the rest of overclock.net could find you a good setup.